In the oil and gas industry, wellbores are drilled into the Earth using drilling rigs, where tubulars are threaded together to form long tubular strings that are inserted into the wellbore to extract the desired fluid. The tubular string is generally suspended in the borehole using a rig floor-mounted spider, such that each new tubular segment or stand may be threaded onto the end of the previous tubular just above the spider. A single-joint elevator is commonly used to grip and secure the segment or stand to a hoist to lift the segment or stand into position for threading the tubular together.
For installing a string of casing, single-joint elevators generally include a pair of hinged body halves that open to receive a tubular segment and subsequently close to secure the tubular segment within the elevator. Single-joint elevators are specifically adapted for securing and lifting tubular segments having a conventional connection, such as an internally-threaded sleeve that receives and secures an externally-threaded end from each of two tubular segments to secure the segments in a generally abutting relationship. The internally-threaded sleeve is first threaded onto the end of a first tubular segment to form a “box end.” The externally-threaded “pin end” of a second tubular segment is then threaded into the box end to complete the connection between the two segments. When the elevator is in the closed position, i.e., when the hinged body halves are secured shut, the internal diameter of the elevator is less than the outer diameter of the box end. Consequently, the circumferential shoulder formed by the elevator engages the tubular segment at a corresponding shoulder formed by the end of the sleeve, thereby preventing the tubular segment from slipping through the elevator.
At least one challenge encountered by typical single-joint elevators is that they are designed to catch a very small range (e.g., outside diameter) of casing. With numerous integral and upset connections currently being used in the field, there are often times variances in the outside diameter of the box end of the casing that prohibit the use of a solitary single-joint elevator. Instead, two or more single-joint elevators are required to accommodate the varying outside diameters of the pipes and/or connections encountered.
What is needed, therefore, is a multi-range, single-joint elevator capable of being secured to tubulars having a range of deviations in the outside diameter thereof.